实施强化预脱硅及间接加热脱硅新技术

脱硅是生产氧化铝的重要工序。通过对脱硅机理的分析和预脱硅条件的实验室研究,合适的预脱硅条件为温度95~100℃、晶种添加量50~80g/L、搅拌反应时间3~4h;工业应用后,提高了预脱硅效率,达到80%以上,减缓了套管加热器结疤生成速度,使间接加热脱硅机运行周期由原来的10天左右延长到3个月以上,提高了溶液浓度,使吨氧化铝蒸汽消耗降低了0.32t。

IMPLEMENTATION OF THE NEW INTENSIFYING TECHNOLOGY OF SILICON PRE-REMOVAL AND SILICON REMOVAL THROUGH INDIRECTLY HEATING

Silicon removal is very important in alumina production.In this paper the proper conditions for silicon pre-removal were determined through analyzing the mechanism of silicon removal and conducting laboratory scale tests.The conditions include the temperature,the seed addition quantity and the agitating and reacting time,which are 95℃ to 100℃,50～80g/L and 3～4 hours respectively.The efficiency of silicon pre-removal was improved,reaching more than 80%,when used in industry scale.The scarring speed of the silicon removal equipment was slowed down,the running period of silicon removal equipment through indirectly heating was extended,prolonged to 3 months,and furthermore,the solution concentration was increased,making the steam consumption per ton aluminum reduced by 0.32t.